Automatic ambient light cancellation for an optical front end. The present disclosure includes a coarse loop and fine loop in a feedback circuit configured to cancel out currents generated by detection of ambient light. An optical front end comprises a single-ended photo-diode connected to a transimpedance amplifier (TIA) followed by a buffer stage to generate differential output. A feedback loop controls a current digital to analog converter (iDAC) which is used to cancel out undesired current (e.g., from ambient light). This results in the TIA from saturating and maintain good signal quality with greater sensitivity.